DE3620700C2 - - Google Patents

Abstract

A method and apparatus for removing sludge from water, including separating the inorganic constituents or matter in the sludge, such as stones, gravel, etc., from the organic matter, such as wood, roots, etc. In a first stage, those constituents that are larger than a given size are separated out from the sludge, with inorganic and organic ones of these constituents being separated from one another, being cleaned, and being then provided for subsequent use. In a second stage, inorganic constituents that are larger than a minimum size are separated out from the remaining matter, are cleaned, and are then provided for subsequent use. In a third stage, water is removed from the inorganic and organic slurry of the remaining matter to form a thick sludge and effluent.

Description

The invention relates to a method for sludge removal Bodies of water and their treatment, first of all from bodies of water Sludge removed and then those contained in the sludge inorganic (stones, gravel, sand etc.) and organic (wood, Roots etc.) components are separated from each other, as well an installation for carrying out the process. The procedure and the plant are equally for the preparation of Sludge sediments suitable.

When processing sludge, a large number of fall Substances that are roughly divided into inorganic and organic components can be divided. With the inorganic components it is mainly stones, gravel, sand etc., while the organic components including wood and roots grasp. Oils must also be added to these organic components are counted, which were led into the waters and ver dirty. There are also chemical contaminants, at for example the introduction of phosphates into the water dissolve in the water.

The aim in removing sludge from water and treating it is to remove it from the free inorganic and organic constituents. However, a big problem is what to do with these Be components should happen when removed from the water have been. Since landfill spaces are becoming increasingly scarce, a goal must be reached to lie in the inorganic and organic components, i.e. stones, gravel, Sand, wood, roots etc., to be won and as a usable host to continue to use assets. Only a fraction of it is said to be landfill. This objective is with the known methods and with the known systems not up to  fullest satisfaction attainable, so that still a big one part of the sludge extracted from the water the landfill rooms charged.

DE-OS 26 17 372 describes a method and a device for cleaning granular materials such as ore rock, gravel, sand, Quartz or the like. The impurities like peat, reeds, Wood, clay or the like, in the granular substances to be cleaned are eliminated in a classifier.

From DE-PS 34 18 492 a device for the treatment of Water deposits known from sands and gravel sands as well as more finely divided and / or lighter ones, in particular particles containing organic constituents, such as digested sludge, Silt and / or debris consist of clay and silt, especially for desludging rivers, ports and lakes. After the removal of such Water deposits by rinsing on land (polders) is no longer possible, is mentioned in the patent proposed the separation of the components of the Optimize water deposits in the individual parts, for which it is essentially proposed that a classifier Fluid bed apparatus is subordinated to the container on his lower end with an inflow base for vortex fluid and a deduction for sands and an upper end with a Overflow for vortex fluid and floating substances as well as a Feeding device for the goods to be sorted is provided. The Classifier is a screening or raking system for removing the Coarse materials and a chopper for coarse shredding upstream. After all, the fluid bed apparatus is one Flocculation station for the more finely divided and / or lighter ones Particles downstream and a buffer tank for the classifying and / or sorting goods before and / or subordinate.  

Starting from the removal of sludge from water and their preparation the beginning given type, the invention has for its object that be known methods to improve so that only small amounts are to be deposited and that the non-deposited components of the sludge as a usable auditor for further use be fed; furthermore, a facility for implementation tion of the procedure.

The invention provides a method as a technical solution beaten, in which one step out of one Mud taken from the water above the components certain size separately and according to inorganic and organic Components sorted out, cleaned and reused be supplied that then in a second stage the remaining components above a certain second Size that is a fraction of the first size, the inorganic components separated, cleaned and also be recycled and that finally in a third stage of residual sludge in the form of an inorganic and / or dewatered organic sludge and thereby the obtained Thick sludge and the waste water processed or abge leads.

Through these process steps there is a perfect separation the inorganic and organic Be contained in the sludge components possible from each other, the individual components fed as reusable economic goods for further use can be. So in the first stage the stones and the Gravel of the inorganic constituents separated out and can for example fed to a gravel storage facility for recycling will. At the same time, the organic components, so for example wood or roots, and are discarded  also passed on for recycling, where, for example burned for energy or composted can. The remaining fine parts are then the fed second stage, where then the remaining inorganic Components, i.e. the sand, separated and for example one Sand storage can be fed for recycling. Left over tiny inorganic, d. H. mineral components in the second stage could not be separated, as well as the fine organic constituents, which in a cloudiness eventually become one third stage where there is drainage is carried out, from which thick sludge is then obtained. This can then be landfilled, composted or burned. The drain water can either be the individual stages or else can also be returned to the water. Through this Processing stages of the sludge are made up of these components won, which to a large extent as assets can be recycled without being deposited have to.

According to a further feature of the invention, it is proposed that that in a preliminary stage to the first stage, the water first together with the components below the first size in particular deposited by a special sieving process and then the first Stage is fed and the pre-dewatered components half the first size after inorganic and organic loading components separately and in this separate form of the first Level to be abandoned. This has the advantage that  Pre-stage to the first stage an even better separation of the coarse components from each other is possible. First, the fine ones parts preferably separated by a sieving process and the first stage fed while the pre-dewatered rough stock parts separated according to inorganic and organic components and given up in this separate form of the first stage the. This has the particular advantage that the wood is flawless is separated from the mineral components.

The separated water is preferably removed when the inorganic components in the second stage of the first stage returned so that the procedure for operating the individual NEN stages simplified.

In a preferred implementation of the method, between in the second and third stages the Phos dissolved in the water phate especially by Fe (III) chloride sulfate or Fe (II) sulfate precipitated and in the third stage with the thick sludge secretes. This preferred implementation of the method will Encountered problem that the water sludge very often with phospha that are dissolved in the water. If the Ab running water is returned to the water, it is not essential easy to remove these phosphates. This happens inventively According to the invention, preferably between the second and third Stage in which the phosphates dissolved in the water are precipitated, so that they separated in the third stage and the thick sludge can be assigned.

In a further preferred embodiment, it is proposed that between the second and third stages the water is neutralized in particular by adding lime milk. This counteracts in particular the problem of acidification of the water by SO ₂ precipitation, which in particular causes the fauna in the water to die. By adding milk of lime, the waste water is neutralized, so that the pH value ideally settles to 7. The lime milk addition also causes precipitation, which can then be added to the thick sludge in the third stage.

In a further preferred embodiment, further suggested that after the third stage possible oil from the Drain water separated and reused and the remaining Drain water into the water or into the existing stages is returned. It is preferably used to separate the Oil from the drain water ver with air or oxygen sets, with air or oxygen particles on the oil add droplets so that the oil / air particles thus formed can float and be carried away by the buoyancy. This step ensures that the Ab running water is freed of possible oil residues, so that Drain water can be easily returned to the water, this drainage water is often of better quality than the water in the body of water itself. This prevents the Drain water must be directed to sewage treatment plants that are nearby of lakes or rivers, however, are very rare. That se Parried oil itself can be recycled, for example Used oil treatment can be supplied. In addition to an oil-free water The chemical flotation process takes place Oxygen demand (COD) and the biochemical oxygen demand (BOD) reduced, with the COD values improving between 20 and 50% can be set.

Before the pneumatic flotation, the drainage is preferably carried out with oil emulsion breaking chemicals to create a Oil sludge added, so that the pneumatic flotation to Se paration of the oil works optimally and thus most of the oil Oil can be separated from the drain water.  

Finally, it is proposed that the Floating and floating particles eliminated, especially filile be tert. As a result, the chemical oxygen demand (COD) significantly reduced.

The plant for carrying out the water purification process is based on a removal device for the sludge and separation devices for inorganic and orga African ingredients characterized by a Classifier for separating the components above a be agreed first size and separation according to inorganic and orga components, a cyclone subordinate to the classifier plant for separating the inorganic components above a certain second size, which is a fraction of the first size lies, from the remaining constituents, as well a centrifuge downstream of the cyclone system for dewatering the inorganic and organic cloudiness of the remaining Be components and transfer into thick sludge. The invention Plant for carrying out the process thus consists of a total of three devices connected in series, namely a classifier, a cyclone system and a centrifuge. With The coarse components of the fine are the classifier components separated and carried out for further use. The fine components are then fed to the cyclone plant, where the sand separated and a sand storage also for further processing evaluation is supplied. The remaining organic fine stock parts and mineral fines in the cyclone system could not be separated, the Centrifuge fed where a drainage takes place and the obtained thick sludge is discharged.

In a preferred embodiment of the system, it is proposed gene that the classifier is a swing classifier with several Bah  NEN is that the vibration classifier is a sieve cyclone with a downstream washing drum is upstream that the sieve cyclone has an upper course and a lower course, the Overflow leads directly to a track of the swing classifier and on this pre-separated water in the sieve cyclone with Be parts below the first size and the Un terlauf leads to the washing drum and the pre-dewatered Be parts above the first size of this gives up, and that in the washing drum contains the inorganic and organic components separated from each other and different paths of the Vibration classifier are supplied. By combining Sieve cyclone, washing drum and swing classifier becomes an opti Male separation of the coarse components separated into inorganic Ingredients and organic ingredients enabled. By doing Sieve cyclone is first a water pre-separation with a Pre-screening of components below the first size taken and directly to the swing classifier via an overflow leads, which is provided with several tracks for this purpose. The Pre-dewatered coarse components of the sieve cyclone, however, are fed via an underflow of the washing drum, which with Baffles are provided that separate the inorganic Coarse components made possible from organic coarse components lichen. These separate components are then made up the washing drum is supplied with separate webs of the vibration classifier leads, in which a further classification of the components is pre can be taken. About this swing classifier Components passed several times and of fine organic and mineral particles cleaned. The combination of sieve cyclone, washing drum and swing classifier has in particular the Advantage that the inorganic and the organic rough stock parts can be separated properly since this with a vibration classifier alone is very difficult because a dynamic classification to separate the with water  soaked wood that is no longer buoyant is not possible is.

Is preferably between the cyclone system and the centrifuge a precipitation station for the precipitation of the Phos dissolved in the water phate especially by Fe (III) chloride sulfate and Fe (II) sulfate switched. Through this precipitation station is simple the phosphates dissolved in the water can be removed. Wei terhin is preferably between the cyclone plant and the Zen trifuge a neutralization station to neutralize the what sers switched especially with milk of lime. Through this neutra lization station by adding lime milk, for example deacidified the water so that it easily and even in bes water condition can be returned. Both at Precipitation of the phosphates as well as the addition of milk of lime the precipitate is removed in the downstream centrifuge separated and discharged with the obtained thick sludge.

Furthermore, in a further preferred embodiment, the System suggested that after the centrifuge a pneumatic Flotation cell with gassing reactor and separation vessel with overflow is arranged for separating oil from the drain water. By the pneumatic flotation cell is an additional one Separation of oil possible, although this is technically very easily done in the pneumatic flotation cell that with its gassing reactor on the oil particles air or acid accumulates so that the oil / air particles due to their buoyancy float in the separation vessel and out by means of an overflow can be worn so that the oil sludge concentrate of Wei for example in a waste oil treatment plant can be led.

Finally, it is proposed that a fil after the centrifuge ter, in particular sand filter or solid state filter, arranged  is the floating and floating particles from the drain water eliminated. As a result, the chemical oxygen demand (COD) significantly reduced.

A more detailed explanation of the invention result from the subsequent description of the drawing, in the a preferred embodiment of a training according to the invention system for performing the desludging process of waters is shown schematically.

The system initially consists of a removal device 1 for the sludge, for example in the form of a cutting head suction dredger. This removal device 1 is equipped with a stone trap 2 , which has, for example, a mesh size of 100 mm and thus captures larger components than 100 mm.

The sediment suspension is fed with the interposition of a men genreglers 3 for the system feed a first separation stage consisting of a sieve cyclone 4 , a washing drum 5 and a vibration classifier 6 . In this first separation stage, the inorganic and organic coarse constituents above a size of, for example, 6 mm are separated from the fine constituents below 6 mm. In the Siebzyklon 4 it is followed by a water pre-separation and pre-separation of the Grobbe constituents mm above 6, so that in an upper run 7, the predeposited water leads with fines below 6 mm abge and is fed via a line 8 to the Schwingklassierer. 6 The pre-dewatered solid suspension in the sieve cyclone 4 with the coarse constituents is fed via an underflow 9 to the washing stream 5 , which is provided with baffles. These cause a separation of the coarse organic components (wood, roots, etc.) from the coarse inorganic components (stones, gravel, sand, etc.), the discharge from the washing drum 5 separately via the line 10 (organic components) and the line 11 (inorganic constituents). Another line 8 ' leads from the washing drum 5 to the swing classifier 6 , and this line 8' leads the fine parts under 6 mm from the washing drum 5 and leads them to the swing classifier 6 .

The vibration classifier 6 consists of four lanes, namely a first lane for water pre-separation and pre-screening from the upper course 7 and the subsequent line 8 , a second lane for the inorganic components from the washing drum 5 via line 11 , a third lane for the organic ones Be constituents also from the washing drum 5 via line 10 and a fourth web for the fine parts under 6 mm from the washing drum 5 via line 8 ' . The first and fourth sheets can also be combined with the fine parts under 6 mm.

The coarse components are repeatedly guided back and forth on the tracks of the vibration classifier 6 and cleaned of fine organic and mineral particles. This applies in particular to the coarse organic constituents in order to wash out these fine particles that may be contaminated with heavy metals. The organic components cleaned in this way are fed from their corresponding path of the vibration classifier 6 to a con tainer 12 , from where the wood and the roots of the combustion are supplied, for example, for energy generation or for positioning. The inorganic coarse constituents are also supplied to a gravel store 13 after their cleaning, which contains stones larger than 6 mm. The gravel in the gravel storage 13 , like the wood and the roots, can be recycled.

By means of a feed pump 14 , the inorganic and organic fine components below a size of 6 mm are fed to a (multi-) cyclone system 15 in suspension. In this cyclone system 15 , the sand is separated between the minimum size 0.063 and 6 mm. The cyclone system 15 is a Schwertrübesortorter 16 with a fresh water or Zentratwas water supply 17 downstream, which feeds the cleaned sand via a Schwingentwässererer 18 a sand storage 19 . The filtrate water from the stepped Schwingentwässerer 18 is recycled to the Schwingklassierer 6 via a line twentieth

The fine mineral constituents below 0.063 mm, which cannot be separated in the cyclone system 15 , and the organic fine constituents are fed via lines 21 (mineral slurry) and 22 (organic slurry) to a reservoir 23 with a homogenizer 24 . From there, the slurry is transported further by means of a feed pump 25 to a centrifuge 26 , which forms the third separation stage after the cyclone system 15 as the second separation stage.

In the line 27 between the reservoir 23 and the centrifuge 26 , a precipitation station 28 is connected, which should precipitate the phosphates dissolved in the water by adding Fe (II) sulfate or Fe (III) chloride sulfate and convert them into sedimentable solids.

Furthermore, a neutralization station 29 is connected in the line 27 between the reservoir 23 and the centrifuge 26 , which acidify and thus neutralize the water by adding, for example, lime milk, and at the same time should provide sedimentation aid. Here, too, it precipitates into a sedimentable solid.

In the centrifuge 26 , the mineral and organic slurry and the precipitates from the stations 28 and 29 are dewatered. The thick sludge obtained is, for example, transferred to a truck 31 via a conveyor belt 30 and fed to landfill, composting, incineration or the like.

The drain water from the centrifuge 26 is finally fed to a pneumatic flotation cell 32 . This consists of two gassing reactors 33 , which are operated, for example, with a compressor. Furthermore, the pneumatic flotation cell 32 consists of a separation vessel 34 with an overflow 35 .

The pneumatic flotation cell 32 serves to separate the oil that may be contained in the drain water. For this purpose, the waste water contaminated with the oil is sent through the two gasification reactors 33 , in which a fine-bubble gas dispersion takes place, the waste water being permeated as completely as possible with the same gas bubbles. The entering into the gassing reactors 33 oil / water system is acted upon in cross-flow with gas, high gas and Wassergeschwin speeds in the gassing reactors 33 for the Anlagungskine tics are required. Due to the prevailing physical conditions (microturbulence and air bubbles in the "status nascendi", combined with the compulsory merging of the oil particles with the gas bubbles), very high adhesion of the hydrophobic oil particles to the gas phase is achieved during the very short residence time in the gassing reactor 33 . The gas bubbles can be formed through a porous tube wall with very uniform openings of small diameter. The actual oil separation then takes place in the downstream, cylin drical separation vessel 34 , the oil / air particles due to their lower density up to the surface ben, the oil-rich phase being discharged via the overflow 35 and the concentrate of the oil sludge in one Container 36 is carried out and collected. From there, the oil sludge can be fed to the waste oil treatment system, for example. The separated emulsion water from the container 36 is returned via line 37 to the pneumatic flotation cell 32 .

In order to improve the oil separation, by means of an addition station 38, oil emulsion breaking chemicals are added to the drain water from the centrifuge 26 to create an oil sludge, these chemicals preferably being surfactants.

The oil-cleaned drain water from the pneumatic flotation cell 32 is introduced after passing a level controller 39 after passing a filter 40 into a receiving trench 41 , which may have an oil barrier 42 . From there, the waste water is returned to the water. The filter 40 is intended to free the drain water from suspended particles and floating materials, whereby sand filters and solid state filters can be used. This significantly reduces the chemical oxygen demand (COD).

The system described can be stationary. she can but also be mobile, d. H. she can use it for her area to be transported. The system can be a single one be compact device in which all elements are contained.

Reference symbol list

1 removal device
2 stone basket
3 flow regulators
4 sieve cyclone
5 washing drum
6 vibration classifiers
7 upper reaches
8 pipe (fine components and water)
8 ′ line (fine components)
9 underflow
10 line (organic coarse components)
11 line (inorganic coarse constituents)
12 containers
13 gravel storage
14 feed pump
15 cyclone system
16 sludge sorters
17 Fresh water or centrate water supply
18 vibratory drainers
19 sand storage
20 line
21 pipe (mineral slurry)
22 pipe (organic turbidity)
23 serving basins
24 homogenizers
25 feed pump
26 centrifuge
27 line
28 precipitation station
29 neutralization station
30 conveyor belt
31 trucks
32 pneumatic floating cells
33 gassing reactor
34 separation vessel
35 upper reaches
36 containers
37 line
38 addition station
39 level controller
40 filters
41 drainage ditch
42 Oil barrier

Claims (15)

1. A process for sludge removal from waters and their preparation on first taken from the sludge from bodies of water, and then the inorganic (stones, gravel, sand, etc.) contained in the sludge and organic (wood, roots etc.) components are separated from one another, characterized characterized in that first in a first stage from the sludge removed from a body of water the components above a certain first size are separated and sorted out according to inorganic and organic components, cleaned and further used, that then in a second stage on the remaining components Above a certain second size, which is a fraction of the first size, the inorganic constituents are separated out, cleaned and also sent for further use and that finally in a third stage the residual sludge is dewatered in the form of an inorganic and / or organic slurry and the won Di sludge and the waste water are processed or discharged. 2. The method according to claim 1, characterized in that in a preliminary stage to the first stage, the water together with the ingredients below the first size in particular separated by a sieving process and then the first Stage is fed and the pre-dewatered components  above the first size according to inorganic and organic Components separately and in this separate form of first stage. 3. The method according to claim 1 or 2, characterized in that the separated water when separating the inorganic Ingredients in the second stage of the first stage leads. 4. The method according to any one of claims 1 to 3, characterized records that between the second and third stages the Phosphates dissolved in water, especially by Fe (III) Chlo ridsulfate or Fe (II) sulfate precipitated and in the third Stage with the thick sludge to be sorted out. 5. The method according to any one of claims 1 to 4, characterized shows that between the second and third stages the Water neutralized especially by adding milk of lime becomes. 6. The method according to any one of claims 1 to 5, characterized records that after the third stage possible oil from Ab running water separated and reused and that remained ne drainage water into the water or in the existing stu fen is returned. 7. The method according to claim 6, characterized in that for Separate the oil from the drain water with air or oxygen is added, whereby air or acid Add particles of material to the oil droplets so that the ge formed oil / air particles due to buoyancy and floating can be dissipated.   8. The method according to claim 6 or 7, characterized in that before the drain water with oil emulsion breaking chemicals to create an oil sludge. 9. The method according to any one of claims 1 to 8, characterized records that from the drain water the floating and floating particles are removed, in particular filtered out. 10. Plant for carrying out the sludge removal and sludge processing method according to one of claims 1 to 9 with a removal device ( 1 ) for the sludge and with separation devices for the inorganic and organic components, characterized by
a classifier ( 6 ) for separating the components above a certain first size and separating them from inorganic and organic components,
a cyclone system ( 15 ) arranged downstream of the classifier ( 6 ) for separating the inorganic constituents above a certain second size, which is present at a fraction of the first size, from the remaining constituents,
and a centrifuge ( 26 ) downstream of the cyclone system ( 15 ) for dewatering the inorganic and organic turbidity of the remaining constituents and transferring them into thick sludge. 11. Plant according to claim 10, characterized in that the classifier is an oscillation classifier ( 6 ) with several tracks, that the oscillation classifier ( 6 ) is preceded by a sieve cyclone ( 4 ) with a downstream washing drum ( 5 ), that the sieve cyclone ( 4 ) an upper course ( 7 ) and a lower course ( 9 ) be seated, wherein the upper course ( 7 ) leads directly to a web of the vibration classifier ( 6 ) and on this in the sieve cyclone ( 4 ) gives up previously separated water with components below the first size and wherein the underflow ( 9 ) leads to the washing drum ( 5 ) and gives up the pre-dewatered components above the first size thereof, and that in the washing drum ( 5 ) the inorganic and organic constituent parts are separated from one another and in each case are fed to different paths of the vibration classifier ( 6 ) . 12. Plant according to claim 10 or 11, characterized in that between the cyclone system ( 15 ) and the centrifuge ( 26 ) has a precipitation station ( 28 ) for precipitating the phosphates dissolved in water, in particular by Fe (III) chloride sulfate and Fe (II) sulfate is switched. 13. Plant according to one of claims 10 to 12, characterized in that between the cyclone system ( 15 ) and the centrifuge ( 26 ), a neutralization station ( 29 ) for neutralizing the water is switched in particular with milk of lime. 14. Plant according to one of claims 10 to 13, characterized in that after the centrifuge ( 26 ), a pneumatic flotation cell ( 32 ) with gassing reactor ( 33 ) and separation vessel ( 34 ) with overflow ( 35 ) for separating oil from the From running water is arranged. 15. Plant according to one of claims 10 to 14, characterized in that after the centrifuge ( 26 ), a filter ( 40 ), in particular sand filter or solid filter, is arranged, which removes the floating and floating particles from the drain water.